PROBLEM

[patch]

Hello all

 

having slight problem with my dimmers at work we have ld 90 dimmers (if this helps in any way for the problem) :) :)

 

When I power up everytime there is always one channel on constantly CHl 26 it has not been grabbed by our desk as I have tried selecting the chnl and rolling it down to no effect and also unpatching the unit on the desk the only time it will go off is when I trip it off. There are no breaks in our DMX as well because I am able to bring up other units its just that one channel all comments greatly appreciated show week is fast approaching

 

if anyone knows where I can get a user manual just so I can try and bring the level of the unit down on the dimmer

 

MUCH APPRECIATED

 

Patch ;)

[pritch]

I don't know the dimmers personally, but a channel stuck on full would often indicate a blown triac.

 

LD90s stuck both off and on have been discussed before: http://www.blue-room.org.uk/index.php?show...aded&start=

[themadhippy]

sounds like a classc case of a blown thyristor,if my memorys correct there not solder to the board but held in place by terminal strip so replacement is easy.

[Just Some Bloke]

I don't know the dimmers personally, but a channel stuck on full would often indicate a blown triac.

We have the same dimmers and it's a 90% probability that it's a triac. Try and find someone who's got some in stock, buy a few (they're only cheap and if one's gone the others will gradually follow) and change it. If you're not sure how to change a triac give me a call when you get your spares and are at the dimmer (my website has contact details).

 

Best of luck,

 

Eric.

[hadyn.williams]

Pretty sure LD90s would be thyristors not Triacs.

[patch]

I think its a triac

[Just Some Bloke]

Pretty sure LD90s would be thyristors not Triacs.

 

Haydn, would you like to read my post again? WE HAVE LD90s - they have a triac. I know this as I've replaced several and it's always (bar 1 occasion) fixed the same problem as the OP.

[karl]

Haydn, would you like to read my post again? WE HAVE LD90s - they have a triac. I know this as I've replaced several and it's always (bar 1 occasion) fixed the same problem as the OP.

Yeah, although the manual calls them power devices or somesuch thing.

 

I replaced one on ours recently and it's pretty straight forward (so long as it is the 2.5Kw type not 5Kw), you just need a screwdriver. Can't remember the part number off the top of my head but I got it from Farnell.

 

PS User manual is available at http://www.strandlighting.com/clientupload..._usermanual.pdf.

 

PPS Having just followed the link in Pritch's post I have discovered it contains the part number in question - I should have looked before posting (just for completeness it is a tpdv840 (Farnell part 9804250)).

[gareth]

Pretty sure LD90s would be thyristors not Triacs.

Having had 240 ways of LD90 under my care in a previous job, I can add my voice to JSBs and confirm that they are definitely triacs.

 

Just goes to show, I guess, that when it comes to solving real-world problems, a degree course is no substitute for some real-world experience :).

[patch]

cheers guys for your imput I found the manual two mins after posting this topic up ** laughs out loud **.

 

thanks once again

 

patch

[Kazeja]

I think you'll find the original 2K5 device was an alternister.

 

To manually turn off the device, locate which dimmer number it is within the rack (between 1 and 24).

 

Select Level from the menu, and then using the cursor left/right and +/- buttons , select dimmer (unless you wish to select all), cursor right and hold down + 'till the dimmer number appears. Cursor right and adjust that dimmer level. If the lamp is still on having set the dimmer manually to off, chances are it's the "Alternister", often mistaken for a triac.

 

However, if it is a 5K circuit, it'll probably be thw SS63 Solid state relay.

[hadyn.williams]

Pretty sure LD90s would be thyristors not Triacs.

Having had 240 ways of LD90 under my care in a previous job, I can add my voice to JSBs and confirm that they are definitely triacs.

 

Just goes to show, I guess, that when it comes to solving real-world problems, a degree course is no substitute for some real-world experience :) .

 

 

Sorry... Was getting confused with EC90s (and I've checked this one before I said it...)

 

As for real world experience I spent half a year wiring up and repairing Strand Permus racks... what fun that was... (Not that I've taken any offence from that comment :)

[gareth]

I think you'll find the original 2K5 device was an alternister ... often mistaken for a triac

Fair play, Andy! Not going to argue with that! :) {In all fairness, although I had the racks apart for various reasons from time to time, in three years I never had to replace an alternister (!) in any of the 240 ways (plus another 12 for houselights) that were installed in the venue I worked at.}